Accident sensing systems typically use accelerometers to determine which safety devices to deploy. For example, a front accelerometer determines the deceleration of the vehicle. The restraints module deploys the front airbag in response to the deceleration being severe or above a predetermined amount. The deceleration corresponds to a crash impact on the front of the vehicle. Side airbag sensors operate in a similar manner in that a laterally mounted acceleration sensor measures the side deceleration on the vehicle due to a crash.
Telematics systems are currently offered by various automakers. Such systems typically contact a response center in response to the deployment of the airbags. The response center then notifies the police that some type of accident has occurred. Such a system, however, does not provide an indication to the severity of the crash.
U.S. Pat. No. 5,969,598 uses a telematics system to generate a signal corresponding to the severity of the crash. The system uses a shock sensor to determine the amount of shock after the airbag deployment. One problem with such a system is that an inadequate response may be provided if several passengers are within the vehicle. That is, too few emergency vehicles and personnel may be initially dispatched to the accident scene.
Therefore, it would be desirable to provide a crash notification system that provides an indication not only to the severity, but to the number of occupants of the vehicle so that adequate personnel may be dispatched to the scene.